Patent GB-626661-A (GB)
Title: An improved method of introducing an amino group into the nucleus of an aromatic compound
IPC: C07C209/02
Filed: 1946-09-02
Abstract: Aromatic compounds in sulphuric acid solution are nuclearly aminated by heating with hydroxylamine, a salt thereof, or a salt of hydroxylamine disulphonic acid with a metal compound wholly dissolved in the sulphuric acid as catalyst.  Preferably the quantity of sulphuric acid should be about ten times the weight of the aromatic compound used and the temperature below 100 DEG  C. Metal compounds instanced are those of vanadium, molybdenum, titanium and iron and the metal may occur in the anion or kation, e.g. vanadyl sulphate or ammonium vanadate.  Mixtures of the metal compounds with thorium, zirconium or mercury compounds may be used and at low temperatures vanadium compounds are the most effective.  The products are dyes or dyestuffs intermediates and for a list of compounds treated and illustrative examples see the Group IV (c) abridgment. Specifications 204,241, 279,205, 280,652, [all in Class 2 (iii)], 348,159 and 564,610 are referred to.  Reference has been directed by the Comptroller to Specification 585,560.ALSO:Aromatic compounds in sulphuric acid solution are nuclearly aminated by heating with hydroxylamine, a salt thereof, or a salt of hydroxylamine disulphonic acid with a metal compound wholly dissolved in the sulphuric acid as catalyst.  Preferably the quantity of sulphuric acid should be about ten times the weight of the aromatic compound used and the temperature below 100 DEG  C. Metal compounds instanced are those of vanadium, molybdenum, titanium and iron, and the metal may occur in the anion or cation, e.g. vanadyl sulphate or ammonium vanadate. Mixtures of the metal compounds with thorium, zirconium or mercury compounds may be used and at low temperatures vanadium compounds are the most effective.  In examples: (1) the effect of different times of heating, temperatures, proportions of sulphuric acid and catalyst, e.g. vanadyl sulphate, ammonium vanadate, ferrous sulphate, molybdenic acid and titanium dioxide, is shown on the reaction of anthraquinone with hydroxylamine sulphate or an equimolar quantity of an alkali metal salt of hydroxylamine disulphonic acid.  The main products are a - and b -amino-anthraquinone, high temperatures favouring the production of the former.  The use of ferrous sulphate results in smaller yields; (2) benzene with hydroxylamine sulphate and 9a) ferrous sulphate yields mixed metanilic, orthanilic and sulphanilic acids and with (b) vanadyl sulphate mainly metanilic acid with some mixed meta-diamino-benzene-sulphonic acids including 1,3-diamino-benzene-5-sulphonic acid.  Naphthalene with hydroxylamine and vanadyl sulphates yields mixed naphthylamine sulphonic acids at 100 DEG  C., which are converted to quinono-imide compounds at higher temperatures.  Anthracene and phenanthrene with hydroxylamine sulphate and molybdenic acid at 100 DEG  C. give mixtures of amino-anthracene- or amino-phenanthrenesulphonic acids respectively, which at higher temperatures are converted to quinonoid compounds; (3) benzanthrone with vanadyl sulphate and hydroxylamine sulphate or an equivalent quantity of potassium hydroxylamine di-sulphonate yields 3-amino-benzanthrone which on fusion with potassium hydroxide gives a black dyestuff.  Similarly benzo-phenone yields mixed amino-benzophenones, mainly the metaamino-isomer with some of the para, which on coupling with the anilide of 2,3-b -hydroxynaphthoic acid give an orange dye; (4) alizarin, anthrarufine, sulphonated anthrarufine, and (6) azobenzene with vanadyl and hydroxylamine sulphates yield mainly a -amino-alizarin, a reddish-blue mordant dyestuff, a reddish-blue acid dyestuff and mixed amino-azo-benzenes respectively; (5) dibenzanthrone, isodibenzanthrone, flavanthrone, indanthrone and tetrabromindigo with vanadyl sulphate or molybdenic acid and varying molar proportions of hydroxylamine used as its sulphate or alkali metal disulphonate gives the correspondingly aminated but not sulphonated dyestuff which, except for that derived from tetra-bromindigo, is fast to chlorine after treatment with chlorine water or hypochlorite; (7) nitrobenzene and (8) dimethylaniline with molybdenic acid or vanadyl sulphate and hydroxylamine sulphate yield ortho-nitraniline and some nitro-diamino derivatives and mixed amino-dimethylanilines with the ortho-isomer predominating respectively.  The mixed amino-dimethylanilines form a brown azo dyestuff with b -naphthol. It is also stated that amino groups may be introduced into a -nitro-naphthalene, a -chloro-1-nitroanthraquinone, 1,5- or 1,8-dinitro-anthraquinone, 1-nitro-anthraquinone-a -sulphonic acid, into azo dyes obtained on diazotization of nitroanilines, nitrotoluidines, and o-, m-, and p-nitro-anisidine, and into triphenylmethane and sulphur dyes such as dehydro-thio-p-toluidine or its sulphonic acid.  Specifications 204,241, 279,205, 280,652, [all in Class 2 (iii)], 348,159 and 564,610 are referred to.  Reference has been directed by the Comptroller to Specification 585,560.